不同湿度土壤中硫酸盐还原菌对碳钢腐蚀的影响

EFFECTS OF SRB ON CORROSION OF CARBON STEEL IN SOILS WITH DIFFERENT HUMIDITIES

利用微生物分析、失重法、交流阻抗测试技术、扫描电镜及表面能谱等方法 ,研究了在不同湿度的同一种土壤中 ,硫酸盐还原菌对碳钢腐蚀的影响规律 .结果表明 ,土壤湿度对菌类生长的影响是显著的 ,硫酸盐还原菌随着湿度的提高呈递增趋势 ;在相同的湿度下 ,接菌土壤中A3钢腐蚀速率和点蚀深度都明显大于灭菌土壤 ,说明硫酸盐还原菌加速了A3钢在土壤的中的腐蚀 ;随着含水量的增大 ,A3钢腐蚀速率首先增大 ,当土壤含水量增大到 15 %～ 2 0 %时 ,腐蚀速率达到最大 ,然后腐蚀速率随着湿度增大而趋于减小 ;最大腐蚀深度出现在土壤含水量为 15

The effects of sulfate reducing bacterial (SRB) on corrosion of carbon steel in a soil with different humidities and in the presence and absence of SRB have been studied.In the study bacterial analyses,weight loss,electrochemical impedance spectroscopy,scanning electron microscopy (SEM) and EDXA were used.The results show that the growth and metabolism of SRB increases with increasing humidity of soil.The corrosion rate and corrosion pitting depth of carbon steel in soil with SRB and with different humidities are larger than those without SRB.Corrosion rate of carbon steel increases with increasing soil humidity and reaches a maximum during 15-20% water content,then decreases with increasing soil humidity.Corrosion pitting depth reaches a maximum during 10-15% water content.The results indicates that corrosion rate of carbon steel increases in soils with SRB.